Georg bernhard ax



G. B. AX.

COMPRESSOR.

APPLICATXON FILED-SEPT. 12. 1917.

Patented June 17, 1919.

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UNITED STATES PATENT OFFICE.

GEoEG BEENHAED Ax, or STOCKHOLM, SWEDEN, AsSIGNoE, BY MESNE ASSIGNMENTS, To LUDWIGSBERGS VERKSTADS AKTIEB'OLAG, 0F STOCKHOLM, SWEDEN.

COMPRESSOR.

Specification of Letters Patent.

Patented June 1'7, 1919.

To all whom it may concern:

Be it known that I, GEORG BERNHARD Ax, a subject of the King of Sweden, and resident of Varfs atan 14, Stockholm, in the [Kingdom of gweden, have invented certain new and useful Improvements in Compressors, of which the following is a specification, reference being had therein to the accompanying drawings. I

In compressors for air or other gases the capacity is, as well known reduced by leaking in valves, conduits and so on, and besides the working cylinder is not completely filled with air during the suction stroke of the piston, due to the fact that there must be a partial vacuum in the said cylinder, in order that the suction valve, acted upon by a spring, may be held in open position by the exterior air and the air may pass into the cylinder. The said vacuum exists also at the end of the suction stroke of the piston. Owing to the said facts, a quantity of air corresponding to a full charge of the cylinder for each stroke of the piston will not be supplied to the accumulator or the like in which the compressed air is stored up,

or to the place in which the compressed air is used. In order to remove the said disadv. ntage, openings have been provided in the wall of the working cylinder, which are so located that, when the piston arrives at the end of its suction stroke, they connect the chamber of the working cylinder with the exterior air, so that air can pass into the said cylinder and remove the said vacuum to a greater or less extent. It happens, however, when the compressor runs at a high rate, that the exterior air, before the piston has turned and shunts off the said openings, has not had time enough to enter the cylinder through the openings to such a quantity that the said vacuum is completely removed. This invention relates to an arrangement in the compressor through which at the end of the section stroke of the piston, air compressed by the piston enters the cylinder through the openings provided in the wall of the cylinder, so that, as the piston starts on its compression stroke, the cylinder not only is completely filled with air but the air in the cylinder has a certain excess of pressure, so that the loss of air due to leaking not only is compensated but a quantity of air arrives at the accumulator during every stroke oi the piston, which is equal to the whole volume of the cylinder and even greater than the same.

In the accompanying shows in a vertical section the lower part of a compressor cylinder arranged in accordance with this invention. Fig. 2 shows, viewed from the under side, a bottom closing a chamber provided below the working cylinder of the compressor.

1, Figs. 1 and 2, is the working cylinder, mounted in a receptacle 2 containing cooling water. 3 is the piston of the cylinder, shown in the position, which it occupies at the end of the suction stroke. 4 denotes the openings mentioned above and provided in thewall of the cylinder 1, which openings are adapted to admit air into the cylinder 1 at the end of the suction stroke of the piston for the purpose mentioned above.

According to this invention a chamber 6 is provided in the receptacle 2, below the cylinder 1, which chamber is closed by a bottom 5. The piston rod 7 passes hermetically through an opening provided in the said bottom 5, and is provided with longitudinal grooves 10, the ends of which are located at some dis tance from the piston. In the bottom 5 openings 8 are provided, which are closed by a ring shaped flap valve 9, which is fixed to the inner side of the bottom 5 and opens inward toward the chamber 6, admitting exterior air into the same. The cylinder 1 is provided, as usual, at its top end with an inlet valve 11 for the air and an outlet valve 12 for the compressed air.

The described compressor operates in the following manner. AS the piston 3 is moved upward from the position shown in Fig. 1, vacuum is created in the chamber 6, so that the valve 9 is opened and air passes through the openings 8 and fills the chamber 6 and the lower part of the cylinder. If the flap valve 9 should stick to its Seat or for any other reason should not be opened, the grooves 10 of the piston rod 7 will nevertheless always admit air into the chamber 6. As the piston is moved downward after the completion of the compression stroke, the valve 9 is closed and the passage through the grooves interrupted so that the air contained in the cylinder chamber located below the piston and in the chamber 6 is compressed. As the piston, at the end of its downward stroke or suction stroke, uncovers the openings 4, the air contained in the chamber drawlngs Figure 1 6 passes into the cylinder 1 through the said openings 4. Owing to the fact that the said air is compressed, the cylinder 1 not only is completely filled with air, even if the piston operates at a high rate, but the air contained in the cylinder has a certain excess of pressure at the beginning of the compression stroke, so that loss of air caused by leaking not only is compensated butthe accumulator is supplied during every stroke of the piston with an air quantity, which is greater than the volume of the cylinder.

Since the longitudinal grooves 10 of the piston rod 7 put the chamber 6 into communication with the outer air, as stated above, the valve 9 may, evidently, be omitted. During the first part of the upward stroke of the piston 3 a partial vacuum will I then be created in the chamber 6, but the chamber will afterward be completely filled with air passing through the grooves 10, which is then compressed during the downward stroke of the piston. The small amount of increased power which is necessary to overcome the said partial vacuum and the slight quantity of air which leaves the chamber 6, before the communication with the outer air through the grooves 10 is interrupted, are in many cases of no importance especially when the compressor operates for a short period for supplying air to an accumulator.

Having now described my invention, what Copies of this patent may be obtained for five cents each, by addressing the I claim as new and desire to secure by Letters Patent is:

1. In a compressor for air or gases, the combination with a working cylinder, the piston operating in the same, and openings provided in the wall of the said cylinder at the inner end of the same so that they are uncovered by the piston at the end of its suction stroke, of a chamber provided at the said end of the cylinder and communicating with the same and with said openings, and longitudinal grooves provided in the rod of the said piston passing through one of the walls of the said chamber, said grooves ending at a distance from the piston.

2. In a compressor for air or gases, the combination with a working cylinder, the piston operating in the same, and openings provided in the wall of the said cylinder at the inner end of the same so that they are uncovered by the piston at the end of its suction stroke, of a chamber provided at the said end of the cylinder and communicating with the same and with the said openings, an air admission valve provided in the said chamber, and longitudinal grooves provided in the rod of the said piston, passing through one of the walls of the said chamber, said grooves ending at a distance from the piston.

In witness whereof, I have hereunto signed my name.

GEORG BERNHARD AX.

Commissioner of Patents,

* Washington, D. C. 

